1. Field of the Invention
The invention relates to an optical switch and an in-line equipment adapted thereto. More specifically, this is a fiber bypass module capable of connecting to the in-line equipment and the in-line equipment for it to connect.
2. Descriptions of the Related Art
With the rapid development of network technology, conventional copper cables for signal transmission are replaced with optical cables gradually. Compared to conventional copper cables, optical cables not only have advantages of small size and immunity from electromagnetic interference, but also can provide rapid and large signal transmission. Therefore, optical network technologies using optical cables as the media for signal transmission are applied to various industries and communications between equipments widely.
Optical switch is a necessary device in an optical network application. Optical switch is one of the important elements in an optical fiber communication network to switch optical signals in the optical network for adjusting optical paths of optical signals. In general, a fiber bypass module has a built-in optical transceiver (otherwise known as O/E Converter), and is provided with multiple optical cables for transmitting optical signal extended therein. The so called optical transceiver may convert an electrical signal into an optical signal for transmission to the optical network equipment through the optical cables provided in the fiber bypass module, and convert a received optical signal into an electrical signal to be transmitted to the in-line equipment. The so called fiber bypass module is connected to the in-line equipment electrically, and is coupled with the optical transceiver and the optical network equipment, respectively, for receiving the signal from the in-line equipment to turn on and off optical signal connection between the optical transceiver and the external optical network equipment. The built-in of the optical transceiver in the fiber bypass module will cause that the manufacturing cost of the fiber bypass module cannot be reduced effectively, and the brand and hardware specification of the optical transceiver in the fiber bypass module cannot be changed arbitrarily.
However, because optical signal is transmitted in optical cable with optical refraction and reflection, the optical cable in the fiber bypass module should have a certain degree of bending radius (in terms of EAI/TIA 568 regulation, the bending radius of multi-mode optical cable shall not be smaller than 25 mm), such that the optical signal may be transmitted in the optical cable continuously without attenuation. As shown in FIG. 1, a fiber bypass module 1 is wound with multiple rounds of optical cables 11, each of the optical cables 11 is wound along an inner housing 12 of the fiber bypass module 1 or on a cable tray (not shown) to change the direction of the optical cable for the bending radius of the optical cable to comply with the standard. Therefore, the size of the fiber bypass module cannot be reduced.
Further, an fiber bypass module has to keep electrical connection with an in-line equipment to receive the signal from the in-line equipment. Therefore, the fiber bypass module is usually arranged in an equipment casing of the in-line equipment. As such, a reserved space in the equipment casing of the in-line equipment is necessary for arranging the fiber bypass module, which size cannot be reduced, such that there is difficulty in arranging and utilizing the internal space of the in-line equipment.
From above, it is the problems that those skilled in the art have to solved urgently about how to arrange a fiber bypass module outside in-line equipment, and keep electrical connection with the in-line equipment.